Lighting System for Growing Plants

ABSTRACT

A lighting system includes a first LED array which includes a plurality of LED sub-arrays, and a plurality of inputs operatively coupled to a corresponding LED sub-array through a controller. The intensity of light emitted by the LED sub-arrays is adjustable in response to adjusting input signals provide by the inputs. In this way, the intensity of light emitted by the LED sub-arrays is adjustable, in response to adjusting the input signals, to drive a wavelength spectrum of the first LED array to match the action spectrum of a physiological activity of a plant.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.12/509,380, filed on Jul. 24, 2009 and issued on Oct. 30, 2012 as U.S.Pat. No. 8,297,782, which claims priority to U.S. ProvisionalApplication No. 61/083,499 filed on Jul. 24, 2008, the contents of bothof which are incorporated by reference as though fully set forth herein.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates generally to facilitating plant growth usinglight.

2. Description of the Related Art

Some lighting systems for growing plants utilize gas-based lights andother lighting systems utilize light emitting diodes (LEDs). Moreinformation regarding lighting systems for growing plants can be foundin U.S. Pat. No. 6,688,759 to Hadjimichael, the contents of which areincorporated herein by reference. Information regarding lighting systemsthat utilize LEDs can be found in U.S. Pat. No. 5,012,609 to Ignatius etal., U.S. Pat. No. 5,278,432 to Ignatius et al., U.S. Pat. No. 6,474,838to Fang et al., U.S. Pat. No. 6,602,275 to Sullivan, U.S. Pat. No.6,921,182 to Anderson et al., U.S. Patent Application Nos. 20040189555to Capen et al., 20070058368 to Partee et al., U.S. Patent ApplicationNo. 20110125296 to Bucove, et al., U.S. Patent Application. No.20050030538 to Jaffar and International Application No.PCT/CA2007/001096 to Tremblay et al., all of which are incorporated byreference as though fully set forth herein.

There are many different manufacturers that use light emitting diodesfor the growing of plants. Some of these manufacturers include HomegrownLights, Inc., which provides the Procyon 100, SuperLED, which providesthe LightBlaze 400, Sunshine Systems, which provides the GrowPanel Pro,Theoreme Innovation, Inc., which provides the TI SmartLamp, and HID Hut,Inc., which provides the LED UFO.

However, it is desirable to provide a lighting system which allows thecolor of the emitted light to be better controlled.

BRIEF SUMMARY OF THE INVENTION

The present invention is directed to a fighting system for facilitatingthe growth of plants. The novel features of the invention are set forthwith particularity in the appended claims. The invention will be bestunderstood from the following description when read in conjunction withthe accompanying drawings.

These and other features, aspects, and advantages of the presentinvention will become better understood with reference to the followingdrawings and description.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 a is a block diagram of a lighting system, which includes twoinputs operatively coupled to an LED array through an LED controller.

FIG. 1 b is a more detailed block diagram of the lighting system of FIG.1 a.

FIG. 1 c is a more detailed front view of one embodiment of the LEDarray of FIG. 1 a, which includes two LED sub-arrays.

FIG. 2 a is a schematic diagram of one input of FIG. 1 a operativelycoupled to one of the LED sub-arrays through an LED driver circuit,wherein the input operates as a potentiometer.

FIG. 2 b is a schematic diagram of the other input of FIG. 1 aoperatively coupled to another of the LED sub-arrays through another LEDdriver circuit 141, wherein the other input operates as a potentiometer.

FIG. 3 a is a graph of a wavelength spectrum of light provided by thelighting system of FIG. 1 a.

FIG. 3 b is a graph of another wavelength spectrum of light provided bythe lighting system of FIG. 1 a.

FIG. 3 c is a graph of a wavelength spectrum of light provided by thelighting system of FIG. 1 a, wherein the wavelength spectrum includescolor mixing.

FIGS. 4 a and 4 b are graphs of wavelength spectra of light provided bythe lighting system of FIG. 1 a, and action spectrum corresponding tochlorophyll a and chlorophyll b, respectively.

FIGS. 4 c and 4 d are graphs of wavelength spectra of light provided bythe lighting system of FIG. 1 a, and action spectrum corresponding toα-carotene.

FIGS. 4 e and 4 f are graphs of wavelength spectra of light provided bythe lighting system of FIG. 1 a, and action spectrum corresponding toβ-carotene.

FIG. 4 g is a graph of wavelength spectrum of light provided by thelighting system of FIG. 1 a, and action spectrum corresponding topelargonin (Perlargonidin-3,5-diglucoside).

FIG. 4 h is a graph of wavelength spectrum of light provided by thelighting system of FIG. 1 a, and action spectrum corresponding tophycocyanin.

FIG. 4 i is a graph of wavelength spectrum of light provided by thelighting system of FIG. 1 a, and action spectrum corresponding tophycoerythrin.

FIGS. 5 a and 5 b are bottom and top perspective views, respectively, ofan embodiment of a lighting system.

FIGS. 5 c and 5 d are top and back perspective views of the lightingsystem of FIGS. 5 a and 5 b.

FIG. 5 e is a front perspective view of the lighting system of FIGS. 5 aand 5 b.

FIG. 5 f is a front view of a first LED array of the lighting system ofFIGS. 5 a and 5 b, wherein the first LED array includes five LEDsub-arrays carried by an LED array support structure.

FIG. 5 g is a front view of a second LED array of the lighting system ofFIGS. 5 a and 5 b, wherein the second LED array includes five LEDsub-arrays carried by an LED array support structure.

FIGS. 6 a and 6 b are block diagram of the lighting system of FIGS. 5 aand 5 b, which includes five inputs operatively coupled to the first andsecond LED arrays through an LED controller, wherein the LED controllerincludes first and second LED sub-controllers.

FIGS. 7 a, 7 b, 7 c, 7 d and 7 e are schematic diagrams of the inputs ofFIGS. 5 a and 5 b operatively coupled to the first LED sub-arraythrough, the first LED driver circuit wherein the inputs operate aspotentiometers.

FIGS. 8 a, 8 b, 8 c, 8 d and 8 e are schematic diagrams of the inputs ofFIGS. 5 a and 5 b operatively coupled to the second LED sub-arraythrough the second LED driver circuit, wherein the inputs operate aspotentiometers.

FIGS. 9 a, 9 b and 9 c are graphs of wavelength spectra of lightprovided by the lighting system of FIGS. 5 a and 5 b, wherein thewavelength spectrum includes color mixing.

FIG. 9 d is a graph of a wavelength spectrum of light provided by thelighting system of FIGS. 5 a and 5 b, wherein, and the wavelengthspectrum of chlorophyll a.

FIG. 9 e is a graph of a wavelength spectrum of light provided by thelighting system of FIGS. 5 a and 5 b, wherein, and the wavelengthspectrum of α-carotene.

FIG. 9 f is a graph of a wavelength spectrum of light provided by thelighting system of FIGS. 5 a and 5 b, wherein, and the wavelengthspectrum of pelargonin.

FIG. 9 g is a graph of a wavelength spectrum of light provided by thelighting system of FIGS. 5 a and 5 b, wherein, and the wavelengthspectrum of sunlight.

FIG. 10 is a block diagram of a lighting system, which includes aprogrammable logic controller operatively coupled to an LED arraythrough an LED controller.

DETAILED DESCRIPTION OF THE INVENTION

FIG. 1 a is a block diagram of a lighting system 100 a, which includesinputs 110 and 111 operatively coupled to an LED array 102 through anLED controller 130. Lighting system 100 a includes a power supply 108which provides a power signal S_(Power) to LED controller 130 through apower terminal 108 a.

LED array 102 includes two or more different types of LEDs, which arecapable of emitting different wavelength spectrums of light. LEDs of thesame type emit the same wavelength spectrums of light, and LEDs ofdifferent types emit different wavelength spectrum of light. Awavelength spectrum of light is the intensity of light emitted by theLED versus the wavelength of the light, and corresponds to a color ofthe light. The wavelengths spectrum of light can be determined in manydifferent ways, such as with a spectrometer. Examples of wavelengthspectrums of light are discussed in more detail below with the graphsshown in FIGS. 3 a-3 c and FIGS. 4 a-4 i.

It should be noted that the conventions for the wavelengths of differentcolors of light vary widely. However, the wavelengths of light discussedherein will have the following ranges for ease of discussion:

-   -   Ultraviolet light (UV): 40 nm to 380 nm;    -   Violet light: 380 nm to 450 nm;    -   Blue light: 450 nm to 495 nm;    -   Green light 495 nm to 570 nm;    -   Yellow light: 570 nm to 590 nm;    -   Orange light: 590 nm to 620 nm;    -   Red light: 620 nm to 750 nm; and    -   Infrared light (IR): 750 nm to 2500 nm,        wherein the wavelengths above are in nanometers (nm).

It should also be noted that there is typically some wavelength overlapbetween adjacent colors of light emitted by an LED. For example,wavelengths of blue and green light emitted by an LED typically overlapin a wavelength range of about 485 nanometers to about 505 nanometers.Further, wavelengths of blue and violet light emitted by an LEDtypically overlap in a wavelength range of about 440 nm to about 460 nm.In this way, the wavelength range of blue light is between about 450 nmto about 495 nm, and the wavelength range of green light is betweenabout 495 nm to about 570 nm.

should be noted that an LED emits light in response to being activated,and an LED does not emit light in response to being deactivated. An LEDis activated in response to driving a current through it to a currentlevel above a threshold current level. Further, an LED is deactivated inresponse to driving a current through it to a current level below thethreshold current level. In this embodiment, an LED of LED array 102 isactivated in response to receiving a signal from LED controller 130, aswill be discussed in more detail below.

It should be noted that the light emitted by two different types of LEDsof LED array 102 are mixed together. In this way, lighting system 100 aprovides color mixing. The light of the LEDs of LED array 102 can bemixed together to provide a desired wavelength spectrum of light.

It should also be noted that the intensity of the light emitted by asingle LED typically has a Gaussian wavelength distribution. However,some LEDs, such as those which provide white light, have intensitiesthat have non-Gaussian wavelength distributions. An LED which provideswhite light and has an intensity having a non-Gaussian wavelengthdistribution will be discussed in more detail below with FIG. 9 g.

The wavelength spectrum of the light emitted by an LED can be chosen inresponse to choosing the band gap energy of the semiconductor materialof the LED. The band gap energy of the semiconductor material of the LEDis typically chosen by choosing the semiconductor material composition.The semiconductor material composition can be chosen during growth. Itshould be noted that the wavelength distribution of the light emitted byan LED can be chosen in response to choosing the semiconductor materialcomposition. The semiconductor materials included with different typesof LEDs can be of many different types, several of which will bediscussed in more detail presently.

LEDs which emit IR light can include many different types ofsemiconductor materials, such as gallium arsenide and aluminum galliumarsenide. Further, LEDs which emit red light can include many differenttypes of semiconductor materials, such as aluminum gallium arsenide,gallium arsenide phosphide, aluminum gallium indium phosphide andgallium phosphide.

LEDs which emit orange light can include many different types ofsemiconductor materials, such as gallium arsenide phosphide, aluminumgallium indium phosphide and gallium phosphide. Further, LEDs which emityellow light can include many different types of semiconductormaterials, such as gallium arsenide phosphide, aluminum gallium indiumphosphide and gallium phosphide.

LEDs which emit green light can include many different types ofsemiconductor materials, such as indium gallium nitride/gallium, nitrideheterostructure, gallium phosphide, aluminum gallium indium phosphideand aluminum, gallium phosphide. Further, LEDs which emit blue light caninclude many different types of semiconductor materials, such as zincselenide and indium gallium nitride.

LEDs which emit violet light can include many different types ofsemiconductor materials, such as indium gallium nitride. Further, LEDswhich emit ultraviolet light can include many different types ofsemiconductor materials, such as aluminum nitride, aluminum galliumnitride, and aluminum gallium indium nitride.

LEDs which emit purple light typically include a blue LED coated with ared phosphor or a white LED coated with a purple plastic. LEDs whichemit white light can include a blue LED coated with a yellow phosphor.

Hence, the LEDs of LED array 102 can provide light having many differentwavelength values, such as those mentioned above. The LEDs of LED array102 can be provided by many different manufacturers, such as Cree, Inc.of Durham, N.C. and Nichia Corporation of Tokyo, Japan. In thisparticular embodiment, however, the LEDs of LED array 102 are providedby Philips Lumileds Lighting Company and are referred to as Luxeon-IIIlight emitting diodes.

In operation, power supply 108 provides power signal S_(Power) to LEDcontroller 130 through power terminal 108 a. LED controller 130selectively controls the operation of the LEDs of LED array 102 inresponse to an indication from inputs 110 and/or 111, as will bediscussed in more detail below. LED controller 130 selectively controlsthe operation of the LEDs of LED array 102 by controlling which types ofLEDs are activated and deactivated. As mentioned above, activated LEDsemit light, and deactivated LEDs do not emit light. In this way, LEDarray 102 is capable of selectively emitting light of differentwavelength ranges.

In one embodiment, LED array 102 includes a first LED which emits redlight and a second LED which emits blue light. In this embodiment, LEDarray 102 can provide red light, blue light and a mixture of red andblue light in response to adjusting inputs 110 and/or 111.

In another embodiment, LED array 102 includes a first LED which emitsviolet light and a second LED which emits red light. In this embodiment,LED array 102 can provide violet light, red light and a mixture ofviolet and red light in response to adjusting inputs 110 and/or 111.

In one embodiment, LED array 102 includes a first LED which emits violetlight and a second LED which emits blue light. In this embodiment, LEDarray 102 can provide violet light, blue light and a mixture of violetand blue light in response to adjusting inputs 111 and/or 110.

FIG. 1 b is a more detailed block diagram of lighting system 100 a, andFIG. 1 c is a more detailed front view of one embodiment of LED array102. In this embodiment, LED controller 130 includes an LEDsub-controller 131, which is operatively coupled to inputs 110 and 111,as well as to LED array 102. In particular, LED sub-controller 131includes LED driver circuits 140 and 141, and LED array 102 includes LEDsub-arrays 120 and 121. Input 110 is operatively coupled to LEDsub-array 120 through LED driver circuit 140, and input 111 isoperatively coupled to LED sub-array 121 through LED driver circuit 141.In this way, inputs 110 and 111 are operatively coupled to LED array 102through LED controller 130.

In this embodiment, LED array 102 includes an LED array supportstructure 106 a which carries LED sub-arrays 120 and 121. In thisembodiment LED sub-array 120 includes one or more LEDs of the same type.Further, in this embodiment, LED sub-array 121 includes one or more LEDsof the same type. The LEDs of LED sub-array 120 are denoted as LEDs 120a, and the LEDs of LED sub-array 121 are denoted as LEDs 121 a. In thisembodiment, and for illustrative purposes, LEDs 120 a is capable ofemitting blue light 162 and LEDs 121 a is capable of emitting red light166. It should be noted that, in general, LED array 102 includes one ormore LED sub-arrays. However, two LED sub-arrays are shown in FIG. 1 cfor simplicity and ease of discussion. An embodiment in which LED array102 includes five LED sub-arrays will be discussed in more detail below.

In operation, power supply 108 (FIG. 1 a) provides power signal to LEDdriver circuits 140 and 141 through power terminal 108 a (FIG. 1 a).Input 110 provides an input signal S_(Input1) to LED driver circuit 140and, in response, LED driver circuit 140 provides an output signalS_(Output1) to LED sub-array 120. Further, input 111 provides an inputsignal S_(Input2) to LED driver circuit 141 and, in response, LED drivercircuit 141 provides an output signal S_(Output2) to LED sub-array 121.

In some embodiments, input 110 operates as a switch, which is repeatablymoveable between active and deactive conditions. In some situations,input 110 is activated so that input signal S_(Input1) provides anindication to LED driver circuit 140 that it is desirable to activatethe LEDs of LED sub-array 120. In response to the indication that it isdesirable to activate the LEDs of LED sub-array 120, LED driver circuit140 provides output signal S_(Output1) to LED sub-array 120, and LEDs120 a are activated so they emit light.

In some situations, input 110 is deactivated so that input signalS_(Input1) provides an indication to LED driver circuit 140 that it isdesirable to deactivate the LEDs of LED sub-array 120. In response tothe indication that it is desirable to deactivate the LEDs of LEDsub-array 120, LED driver circuit 140 provides output signal S_(Output1)to LED sub-array 120, and LEDs 120 a are deactivated so they do not emitblue light 162.

In some embodiments, input 111 operates as a switch, which is repeatablymoveable between active and deactive conditions. In some situations,input 111 is activated so that input signal S_(Input2) provides anindication to LED driver circuit 141 that it is desirable to activatethe LEDs of LED sub-array 121. In response to the indication that it isdesirable to activate the LEDs of LED sub-array 121, LED driver circuit141 provides output signal S_(Output2) to LED sub-array 121, and LEDs121 a are activated so they emit red light 166.

In some situations, input 111 is deactivated so that input signalS_(Input2) provides an indication to LED driver circuit 141 that it isdesirable to deactivate the LEDs of LED sub-array 121. In response tothe indication that it is desirable to deactivate the LEDs of LEDsub-array 121, LED driver circuit 141 provides output signal S_(Output2)to LED sub-array 121, and LEDs 121 a are deactivated so they do not emitred light 166. In this way, LED array 102 is capable of selectivelyemitting light of different wavelength ranges.

FIG. 2 a is a schematic diagram of input 110 operatively coupled to LEDsub-array 120 through LED driver circuit 140, wherein input 110 operatesas a potentiometer. In this embodiment, input 110 includes apotentiometer 137 a, which is connected between power terminal 108 a anda current return 136. LED driver circuit 140 includes an LED driver chip150, which is embodied as an LT3477EFE chip manufactured by LinearTechnology, Inc. of Milpitas, Calif. The LT3477EFE chip is connected toelectrical components, such as a resistor, inductor, capacitor and aSchottky diode, so that it operates as an LED driver. More informationregarding the LT3477EFE chip, and how it is connected to the electricalcomponents to operate as an LED driver, can be found in a correspondingData Sheet provided by Linear Technology, Inc.

In this embodiment power terminal 108 a is connected to terminals 1 and13 of the LT3477EFE chip, and the output of the potentiometer isconnected to terminal 10 so that terminal 10 receives input signalS_(Input1). Terminal 14 of the LT3477EFE chip provides output signalS_(Output1) to LED sub-array 120. In particular, terminal 14 of theLT3477EFE chip provides output signal S_(Output1) to LED 120 a.

In operation, the power of input signal S_(Input1) is adjustable inresponse to adjusting potentiometer 137 a. In one situation, the powerof input signal S_(Input1) is increased in response to adjustingpotentiometer 137 a. LED driver circuit chip 150 increases the power ofoutput signal S_(Output1) in response to the power of input signalS_(Input1) being increased by potentiometer 137 a. The intensity of bluelight 162 emitted by LED 120 a increases in response to the amount ofpower of output signal S_(Output1) being increased by LED driver circuitchip 150.

In another situation, the power of input signal S_(Input1) is decreasedin response to adjusting potentiometer 137 a. LED driver circuit chip150 decreases the power of output signal S_(Output1) in response to thepower of input signal S_(Input1) being decreased by potentiometer 137 a.The intensity of blue light 162 emitted by LED 120 a decreases inresponse to the amount of power of output signal S_(Output1) beingdecreased by LED driver circuit chip 150.

FIG. 2 b is a schematic diagram of input 111 operatively coupled to LEOsub-array 121 through LED driver circuit 141, wherein input 111 operatesas a potentiometer. In this embodiment, input 111 is embodied as apotentiometer 137 b, which is connected between power terminal 108 a andcurrent return 136. LED driver circuit 141 includes an LED driver chip151, which is embodied as the LT3477EFE chip described in more detailabove. The LT3477EFE chip of LED driver chip 151 is connected toelectrical components, such as a resistor, inductor, capacitor and aSchottky diode, so that it operates as an LED driver.

In this embodiment, power terminal 108 a is connected to terminals 1 and13 of the LT3477EFE chip, and the output of the potentiometer isconnected to terminal 10 so that terminal 10 receives input signalS_(Input2). Terminal 14 of the LT3477EFE chip provides output signalS_(Output2) to LED sub-array 121. In particular, terminal 14 of theLT3477EFE chip provides output signal S_(Output2) to LED 121 a.

In operation, the power of input signal S_(Input2) is adjustable inresponse to adjusting potentiometer 137 b. In one situation, the powerof input signal S_(Input2) is increased in response to adjustingpotentiometer 137 b. LED driver circuit chip 151 increases the power ofoutput signal S_(Output2) in response to the power of input signal beingincreased by potentiometer 137 b. The intensity of red light 166 emittedby LED 121 a increases in response to the amount of power of outputsignal S_(Output2) being increased by LED driver circuit chip 151.

In another situation, the power of input signal S_(Input2) is decreasedin response to adjusting potentiometer 137 b. LED driver circuit chip151 decreases the power of output signal S_(Output2) in response to thepower of input signal S_(Input2) being decreased by potentiometer 137 b.The intensity of red light 166 emitted by LED 121 a decreases inresponse to the amount of power of output signal S_(Output2) beingdecreased by LED driver circuit chip 151.

FIG. 3 a is a graph of a wavelength spectrum 180 of light provided bylighting system 100 a. In FIG. 3 a, wavelength spectrum 180 correspondsto the intensity of light versus wavelength (nm). The intensity of lightis denoted as I₁, I₂, I₃ and I₄, wherein I₁ is less than I₂, I₂ is lessthan I₃ and I₃ is less than I₄. The intensity of light can be determinedin many different ways, such as by using a spectrometer.

In this situation, input 110 provides signal S_(Input1) to LED drivercircuit 140 (FIGS. 1 b and 2 a), and LED driver circuit 140 providessignal S_(Output1) to LED sub-array 120, wherein LED sub-array 120includes LED 120 a. In this particular example, LED 120 a is an LED thatemits blue light 162 when activated. As shown in FIG. 3 a, blue light162 has a Gaussian wavelength spectrum 180 a between about 450 nm and495 nm. In some examples, blue light 162 has a Gaussian wavelengthspectrum 180 a between about 475 nm and 500 nm. In some examples, bluelight 162 has a Gaussian wavelength spectrum 180 a between about 450 nmand 475 nm. It should be noted that the intensity of blue light 162 ofwavelength spectrum 180 can be adjusted in many different ways, severalof which will be discussed in more detail presently.

As mentioned above, in some embodiments, input 110 operates as a switchwhich is repeatably moveable between activated and deactivatedconditions. In these embodiments, the intensity of blue light 162provided by LED sub-array 120 is adjustable in response to adjusting thenumber of LEDs 120 a. For example, the intensity of blue light 162decreases, as indicated by wavelength spectrum 180 b, in response todecreasing the number of LEDs 120 a of LED sub-array 120. Further, theintensity of blue light 162 increases, as indicated by wavelengthspectrum 180 c, in response to increasing the number of LEDs 120 a ofLED sub-array 120.

Further, in other embodiments, input 110 includes potentiometer 137 a.In some situations, potentiometer 137 a is adjusted so the power ofinput signal S_(Input1) and output signal S_(Output1) are decreased, asdiscussed above with FIG. 2 a. The intensity of blue light 162decreases, as indicated by wavelength spectrum 180 b, in response todecreasing the power of input signal S_(Input1) and output signalS_(Output1) with potentiometer 137 a.

In some situations, potentiometer 137 a is adjusted so the power ofinput signal S_(Input1) and output signal S_(Output1) are increased, asdiscussed above with FIG. 2 a. The intensity of blue light 162increases, as indicated by wavelength spectrum 180 c, in response toincreasing the power of input signal S_(Input1) and output signalS_(Output1) with potentiometer 137 a.

FIG. 3 b is a graph of a wavelength spectrum 181 of light provided bylighting system 100 a. In FIG. 3 b, wavelength spectrum 181 correspondsto the intensity of light versus wavelength (nm), as discussed abovewith wavelength spectrum 180.

In this situation, input 111 provides signal S_(Input1) to LED drivercircuit 141 (FIGS. 1 b and 2 b), and LED driver circuit 141 providessignal S_(Output1) to LED sub-array 121, wherein LED sub-array 121includes LED 121 a. In this particular example, LED 121 a is an LED thatemits red light 166 when activated. As shown in FIG. 3 b, red light 166has a Gaussian wavelength spectrum 181 a between about 650 nm and 750nm. In some examples, red light 166 has a Gaussian wavelength spectrum181 a between about 620 nm and 670 nm. In some examples, red light 166has a Gaussian wavelength spectrum 181 a between about 700 nm and 750nm. It should be noted that the intensity of red light 166 of wavelengthspectrum 181 can be adjusted in many different ways, several of whichwill be discussed in more detail presently.

As mentioned above, in some embodiments, input 111 operates as a switchwhich is repeatably moveable between activated and deactivatedconditions. In these embodiments, the intensity of red light 166provided by LED sub-array 121 is adjustable in response to adjusting thenumber of LEDs 121 a. For example, the intensity of red light 166decreases, as indicated by wavelength spectrum 181 b, in response todecreasing the number of LEDs 121 a of LED sub-array 121. Further, theintensity of red light 166 increases, as indicated by wavelengthspectrum 181 c, in response to increasing the number of LEDs 121 a ofLED sub-array 121.

Further, in other embodiments, input 111 includes potentiometer 137 b.In some situations, potentiometer 137 b is adjusted so the power ofinput signal S_(Input2) and output signal S_(Output2) are decreased, asdiscussed above with FIG. 2 b. The intensity of red light 166 decreases,as indicated by wavelength spectrum 181 b, in response to decreasing thepower of input signal S_(Input2) and output signal S_(Output2) withpotentiometer 137 b.

In some situations, potentiometer 137 b is adjusted so the power ofinput signal and output signal S_(Output2) are increased, as discussedabove with FIG. 2 b. The intensity of red light 166 increases, asindicated by wavelength spectrum 181 c, in response to increasing thepower of input signal S_(Input2) and output signal S_(Output2) withpotentiometer 137 b.

As mentioned above, lighting system 100 a can provide color mixing whenLED array 102 includes different types of LEDs. An example of awavelength spectrum, with color mixing will be discussed in more detailpresently.

FIG. 3 c is a graph of a wavelength spectrum 182 of light provided bylighting system 100 a, wherein wavelength spectrum 182 includes colormixing. In FIG. 3 c, wavelength spectrum 182 corresponds to theintensity of light versus wavelength (nm), as discussed above withwavelength spectrum 180. As shown in FIG. 3 c, blue light 162 has aGaussian wavelength spectrum 180 a between about 450 nm and 500 nm, andred light 166 has a Gaussian wavelength spectrum 181 a between about 650nm and 750 nm. Lighting system 100 a can provide wavelength, spectrum182 with color mixing in many different ways.

In one embodiment, inputs 110 and 111 operate as switches, which arerepeatably moveable between activated and deactivated conditions. Inthese embodiments, the intensity of blue light 162 provided by LEDsub-array 120 is adjustable in response to adjusting the number of LEDs120 a. For example, the intensity of blue light 162 decreases, asindicated by wavelength spectrum 180 b, in response to decreasing thenumber of LEDs 120 a of LED sub-array 120. Further, the intensity ofblue light 162 increases, as indicated by wavelength spectrum 180 c, inresponse to increasing the number of LEDs 120 a of LED sub-array 120.

In these embodiments, the intensity of red light 166 provided by LEDsub-array 121 is adjustable in response to adjusting the number of LEDs121 a. For example, the intensity of red light 166 decreases, asindicated by wavelength spectrum 181 b, in response to decreasing thenumber of LEDs 121 a of LED sub-array 121. Further, the intensity of redlight 166 increases, as indicated by wavelength spectrum 181 c, inresponse to increasing the number of LEDs 121 a of LED sub-array 121.

It should be noted, that the relative intensities of blue light 162 andred light 166 provided by lighting system 100 a can be adjusted relativeto each other in response to adjusting the number of LEDs 120 a of LEDsub-array 120 and the number of LEDs 121 a of LED sub-array 121. Therelative intensities of blue light 162 and red light 166 can be adjustedin many different ways.

For example, in one situation, the number of LEDs 120 a can be increasedrelative to the number of LEDs 121 a, so that wavelength spectrum 180 cand wavelength spectrum 181 b are provided by LED sub-arrays 120 and121, respectively. In this way, the amount of blue light 162 and redlight 166 provided by lighting system 100 a is increased relative to theamount of red light 166. Further, the number of LEDs 121 a can bedecreased relative to the number of LEDs 120 a, so that wavelengthspectrum 180 c and wavelength spectrum 181 b are provided by LEDsub-arrays 120 and 121, respectively. In this way, the amount of bluelight 162 and red light 166 provided by lighting system 100 a isdecreased relative to the amount of red light 166. In this way, lightingsystem 100 a is capable of providing a desired mixture of blue and redlight.

In other embodiments, inputs 110 and 111 include potentiometers 136 aand 136 b, respectively. In some situations, potentiometer 137 a isadjusted so the power of input signal S_(Input1) and output signalS_(Output1) are decreased, as discussed above with FIG. 2 a. Theintensity of blue light 162 decreases, as indicated by wavelengthspectrum 180 b, in response to decreasing the power of input signalS_(Input1) and output signal S_(Output1) with potentiometer 137 a.

In some situations, potentiometer 137 a is adjusted so the power ofinput signal S_(Input1) and output signal S_(Output1) are increased, asdiscussed above with FIG. 2 a. The intensity of blue light 162increases, as indicated by wavelength spectrum 180 c, in response toincreasing the power of input signal S_(Input1) and output signalS_(Output1) with potentiometer 137 a.

In some situations, potentiometer 137 b is adjusted so the power ofinput signal S_(Input2) and output signal S_(Output2) are decreased, asdiscussed above with FIG. 2 b. The intensity of red light 166 decreases,as indicated by wavelength spectrum 181 b, in response to decreasing thepower of input signal S_(Input2) and output signal S_(Output2) withpotentiometer 137 b.

In some situations, potentiometer 137 b is adjusted so the power ofinput signal S_(Input2) and output signal S_(Output2) are increased, asdiscussed above with FIG. 2 b. The intensity of red light 166 increases,as indicated by wavelength spectrum 181 c, in response to increasing thepower of input signal S_(Input2) and output signal S_(Output2) withpotentiometer 137 b.

It should be noted that the relative intensities of blue light 162 andred light 166 can be adjusted relative to each other in response toadjusting potentiometers 136 a and/or 136 b. The relative intensities ofblue light 162 and red light 166 can be adjusted in many different waysby adjusting potentiometers 136 a and 136 b.

For example, in some situations, it may be desirable to provide moreblue light 162 and less red light 166 with lighting system 100 a. Inthis situation, potentiometer 137 a is adjusted, as described above, sothat input signal S_(Input3) and output signal S_(Output3) have morepower, and wavelength spectrum 180 c is provided by LED sub-array 120.Further, potentiometer 137 b is adjusted, as described above, so thatinput signal S_(Input2) and output signal S_(Output 2) have less power,and wavelength spectrum 181 b is provided by LED sub-array 121. In thisway, lighting system 100 a provides more blue light 162 and less redlight 166.

In some situations, the intensity of red light 166 is about one order ofmagnitude greater than the intensity of blue light 162. In anothersituation, the intensity of red light 166 is about ten to about fifteentimes greater than the intensity of blue light 162. In anothersituation, the intensity of red light 166 is about eight to thirteentimes greater than the intensity of blue light 162. In general, theintensity of red light 166 is a desired amount greater than theintensity of blue light 162.

In some situations, the intensity of blue light 162 is about one orderof magnitude greater than the intensity of red light 166. In anothersituation, the intensity of blue light 162 is about ten to about fifteentimes greater than the intensity of red light 166. In another situation,the intensity of blue light 162 is about eight to thirteen times greaterthan the intensity of red light 166. In general, the intensity of bluelight 162 is a desired amount greater than the intensity of red light166.

In another situation, it may be desirable to provide less blue light 162and more red light 166 with lighting system 100 a. In this situation,potentiometer 137 a is adjusted, as described above, so that inputsignal S_(Input1) and output signal S_(Output1) have less power, andwavelength spectrum 180 b is provided by LED sub-array 120. Further,potentiometer 137 b is adjusted, as described above, so that inputsignal S_(Input2) and output signal S_(Output2) have more power, andwavelength spectrum 181 c is provided by LED sub-array 121. In this way,lighting system 100 a provides less blue light 162 and more red light166. It should be noted that the desired mixture of light provided bylighting system 100 a can be chosen to correspond to an action spectrumof a physiological activity of a plant, as will be discussed in moredetail presently.

FIGS. 4 a and 4 b are graphs of wavelength spectrum 183 and 184,respectively, of light provided by lighting system 100 a. Actionspectrum corresponding to chlorophyll a and chlorophyll b are also shownin FIGS. 4 a and 4 b, respectively. In FIGS. 4 a and 4 b, wavelengthspectrums 183 and 184 correspond to the intensity of light versuswavelength (nm), as discussed above with wavelength spectrum 180.

It should be noted that the action spectrum of chlorophyll a andchlorophyll b of FIGS. 4 a and 4 b, respectively, as well as the otheraction spectra discussed herein, are from a book entitled Introductionto Plant Physiology, 2nd Edition, by William G. Hopkins, which waspublished in 1999 by John Wiley & Sons. An action spectrum is the rateof a physiological activity versus the wavelength of light received by aplant. An action spectrum illustrates which wavelengths of light areeffective in driving the physiological activity, wherein thephysiological activity corresponds to a chemical reaction of the plant.The physiological activity of the plant can be of many different types,such as the chemical reactions associated with photosynthesis andcellular respiration. The wavelengths of light that are effective indriving the physiological activity of the plant depends on the types ofpigments the plant includes.

Plants can include many different types of pigments, such aschlorophylls, carotenoids and phycobilins. There are many differenttypes of chlorophylls, such as chlorophyll a and chlorophyll b. further,there are many different types of carotenoids, such as xanthophylls andcarotenes. There are many different types of carotenes, such asα-carotene and β-carotene. There are many different types ofphycobilins, such as pelargonidin, phycocyanin, phycoerythrin,phytochrome and anthocyanins, among others. It should also be noted thatthe action, spectrum of chlorophyll a and chlorophyll b is similar tothe action spectrum of other chemicals, such as those associated withleaf extract.

For example, the red and blue-violet spectrums of light are effective indriving the physiological activity of photosynthesis of chlorophyll aand chlorophyll b. Hence, the action spectrum corresponding tochlorophyll a and chlorophyll b are non-zero in a range of wavelengthsthat include red and blue-violet light. In this way, the rate ofphotosynthesis of chlorophyll a and chlorophyll b increases in responseto receiving more red and blue-violet light. Further, the rate ofphotosynthesis of chlorophyll a and chlorophyll b decreases in responseto receiving less red and blue-violet light.

In the situation of FIG. 4 a, input 110 provides signal S_(Input1) toLED driver circuit 140, and LED driver circuit 140 provides signalS_(Output1) to LED sub-array 120, wherein LED sub-array 120 includes LED120 a. In this particular example, LED 120 a is an LED that emits violetlight 161 when activated. As shown in FIG. 4 a, violet light 161 has aGaussian wavelength spectrum 183 a between about 400 nm and 450 nm. Insome examples, violet light 161 has a Gaussian wavelength spectrum 183 abetween about 380 nm and 425 nm. In some examples, violet light 161 hasa Gaussian wavelength spectrum 183 a between about 425 nm and 450 nm.

Further, in this situation, input 111 provides signal S_(Input2) to LEDdriver circuit 141, and LED driver circuit 141 provides signalS_(Output2) to LED sub-array 121, wherein LED sub-array 121 includes LED121 a. In this particular example, LED 121 a is an LED that emits redlight 166 when activated. As shown in FIG. 4 a, red light 166 has aGaussian wavelength spectrum 183 b between about 650 nm and 675 nm. Inthis way, lighting system 100 a is capable of providing a wavelengthspectrum which corresponds to the action spectrum of chlorophyll a whenlighting system 100 a includes LEDs capable of emitting violet light 161and red light 166.

As mentioned above, the intensity of the light provided by the differenttypes of LEDs of lighting system 100 a are adjustable relative to eachother. In one embodiment, inputs 110 and 111 correspond to switches sothat the intensity of violet light 161 provided by LED sub-array 120 isadjusted by adjusting the number of LEDs 120 a. Further, the intensityof red light 166 provided by LED sub-array 121 is adjusted by adjustingthe number of LEDs 121 a.

In another embodiment input 110 includes potentiometer 137 a, so thatthe intensity of violet light 161 provided by LED sub-array 120 isadjusted by adjusting potentiometer 137 a, as described in more detailabove. Further, input 111 includes potentiometer 137 b, so that theintensity of red light 166 provided by LED sub-array 121 is adjusted byadjusting potentiometer 137 b, as described in more detail above. Itshould be noted that the relative intensities of violet light 161 andred light 166 can be adjusted relative to each other in response toadjusting potentiometers 136 a and 136 b. In some situations, theintensity of red light 166 is about ten to about fifteen times greaterthan the intensity of violet light 161.

In the situation of FIG. 4 b, input 110 provides signal to LED drivercircuit 140, and LED driver circuit 140 provides signal S_(Output1) toLED sub-array 120, wherein LED sub-array 120 includes LED 120 a. In thisparticular example, LED 120 a is an LED that emits blue-violet light 170when activated. As shown in FIG. 4 b, blue-violet light 170 has aGaussian, wavelength, spectrum 184 a between about 400 nm and 475 nm. Insome examples, blue-violet light 170 has a Gaussian wavelength spectrum184 a between about 450 nm and 500 nm.

Further, in this situation input 111 provides signal S_(Input2) to LEDdriver circuit 141, and LED driver circuit 141 provides signalS_(Output2) to LED sub-array 121, wherein LED sub-array 121 includes LED121 a. In this particular example, LED 121 a is an LED that emits redlight 166 when activated. As shown in FIG. 4 b, red light 166 has aGaussian wavelength spectrum 184 b between about 625 nm and 675 nm. Inthis way, lighting system 100 a is capable of providing a wavelengthspectrum which corresponds to the action spectrum of chlorophyll b whenlighting system 100 a includes LEDs capable of emitting blue-violetlight 170 and red light 166.

As mentioned above, the intensity of the light, provided by thedifferent types of LEDs of lighting system 100 a are adjustable relativeto each other. In one embodiment, inputs 110 and 111 correspond toswitches so that the intensity of blue-violet light 170 provided by LEDsub-array 120 is adjusted by adjusting the number of LEDs 120 a.Further, the intensity of red light 166 provided by LED sub-array 121 isadjusted by adjusting the number of LEDs 121 a.

In another embodiment, input 110 includes potentiometer 137 a, so thatthe intensity of blue-violet light 170 provided by LED sub-array 120 isadjusted by adjusting potentiometer 137 a, as described in more detailabove. Further, input 111 includes potentiometer 137 b, so that theintensity of red light 166 provided by LED sub-array 121 is adjusted byadjusting potentiometer 137 b, as described in more detail above. Itshould be noted that the relative intensities of blue-violet light 170and red light 166 can be adjusted relative to each other in response toadjusting potentiometers 136 a and 136 b.

In general the types of LEDs of lighting system 100 a are chosen so thatlighting system 100 a can provide a wavelength spectrum which drives thephysiological activity of a desired type of plant. Hence, lightingsystem 100 a can provide wavelength spectra useful for plants which haveaction spectrum different from chlorophyll a and chlorophyll b, as willbe discussed in more detail presently.

FIGS. 4 c and 4 d are graphs of wavelength spectrum 185 and 186,respectively, of light provided by lighting system 100 a. Actionspectrum corresponding to α-carotene are also shown in FIGS. 4 c and 4d. FIGS. 4 e and 4 f are graphs of wavelength spectrum 187 and 188,respectively, of light provided by lighting system 100 a. Actionspectrum corresponding to β-carotene are also shown in FIGS. 4 e and 4f, in FIGS. 4 c, 4 d, 4 c and 4 f, the wavelength spectrums correspondto the intensity of light versus wavelength (nm), as discussed abovewith wavelength spectrum 180.

The physiological activity of α-carotene and β-carotene is effectivelydriven by wavelengths of blue-violet light. Hence, the action spectrumcorresponding to α-carotene and β-carotene are non-zero in a range ofwavelengths that include blue and violet light. In this way, the rate ofphysiological activity of α-carotene and β-carotene increases inresponse to receiving more blue-violet light. Further, the rate ofphysiological activity of α-carotene and β-carotene decreases inresponse to receiving less blue-violet light.

In the situation of FIG. 4 c, input 110 provides signal S_(Input1) toLED driver circuit 140, and LED driver circuit 140 provides signalS_(Output1) to LED sub-array 120, wherein LED sub-array 120 includes LED120 a. In this particular example, LED 120 a is an LED that emits violetlight 161 when activated. As shown in FIG. 4 c, violet light 161 has aGaussian wavelength spectrum 185 a between about 400 nm and 450 nm.

Further, in this situation, input 111 provides signal S_(Input2) to LEDdriver circuit 141, and LED driver circuit 141 provides signalS_(Output2) to LED sub-array 121, wherein LED sub-array 121 includes LED121 a. In this particular example, LED 121 a is an LED that emits bluelight 162 when activated. As shown in FIG. 4 c, blue light 162 has aGaussian wavelength spectrum 185 b between about 425 nm and 475 nm. Inthis way, lighting system 100 a is capable of providing a wavelengthspectrum which corresponds to the action spectrum of α-carotene whenlighting system 100 a includes LEDs capable of emitting violet light 161and blue light 162.

As mentioned above, the intensity of the light provided by the differenttypes of LEDs of lighting system 100 a are adjustable relative to eachother. In one embodiment, inputs 110 and 111 correspond to switches sothat the intensity of violet light 161 provided by LED sub-array 120 isadjusted by adjusting the number of LEDs 120 a. Further, the intensityof blue light 162 provided by LED sub-array 121 is adjusted by adjustingthe number of LEDs 121 a.

In another embodiment, input 110 includes potentiometer 137 a, so thatthe intensity of violet light 161 provided by LED sub-array 120 isadjusted by adjusting potentiometer 137 a, as described in more detailabove. Further, input 111 includes potentiometer 137 b, so that theintensity of blue light 162 provided by LED sub-array 121 is adjusted byadjusting potentiometer 137 b, as described in more detail above. Itshould be noted that the relative intensities of violet light 161 andblue light 162 can be adjusted relative to each other in response toadjusting potentiometers 136 a and 136 b. It should also be noted thatthe physiological activity of α-carotene can be driven in response tothe light from one type of LED, as will be discussed in more detailpresently.

In the situation of FIG. 4 d, input 110 provides signal S_(Input1) toLED driver circuit 140, and LED driver circuit 140 provides signalS_(Output1) to LED sub-array 120, wherein LED sub-array 120 includes LED120 a. In this particular example, LED 120 a is an LED that emitsblue-violet light 170 when activated. As shown in FIG. 4 d, blue-violetlight 170 has a Gaussian wavelength spectrum 186 a between about 400 nmand 500 nm. In this way, LED 120 a provides blue-violet light 170 whichhas a broader spectrum than the spectrum of violet light 161 FIG. 4 c.Further, LED 120 a provides blue-violet light 170 which has a broaderspectrum than the spectrum of blue light 162 FIG. 4 c. As mentionedabove, the wavelength distribution of light provided by an LED can bemade broader and narrower in many different ways, such as by choosingthe semiconductor material composition of the LED.

Further, in this situation, input 111 provides input signal S_(Input2)to LED driver circuit 141, and LED driver circuit 141 provides outputsignal S_(Output2) to LED sub-array 121, wherein LED sub-array 121includes LED 121 a. In this particular example, LED 121 a is deactivatedin response to receiving output signal S_(Output2). In this way, thephysiological activity of α-carotene is driven in response to the lightfrom one type of LED.

In one embodiment, inputs 110 and 111 correspond to switches so that theintensity of blue-violet light 170 provided by LED sub-array 120 isadjusted by adjusting the number of LEDs 120 a. Further, the intensityof blue light 162 provided by LED sub-array 121 is adjusted bydeactivating LEDs 121 a.

In another embodiment, input 110 includes potentiometer 137 a, so thatthe intensity of blue-violet light 170 provided by LED sub-array 120 isadjusted by adjusting potentiometer 137 a, as described in more detailabove. Further, input 111 includes potentiometer 137 b, so that theintensity of blue light 162 provided by LED sub-array 121 is adjusted byadjusting potentiometer 137 b so that output signal S_(Output2)deactivates LEDs 121 a.

In the situation of FIG. 4 e, input 110 provides signal S_(Input1) toLED driver circuit 140, and LED driver circuit 140 provides signalS_(Output1) to LED sub-array 120, wherein LED sub-array 120 includes LED120 a. In this particular example, LED 120 a is an LED that emitsblue-violet light 170 when activated. As shown in FIG. 4 c, blue-violetlight 170 has a Gaussian wavelength spectrum 187 a between about 425 nmand 475 nm.

Further, in this situation, input 111 provides signal S_(Input2) to LEDdriver circuit 141, and LED driver circuit 141 provides signalS_(Output2) to LED sub-array 121, wherein LED sub-array 121 includes LED121 a. In this particular example, LED 121 a is an LED that emits bluelight 162 when activated. As shown in FIG. 4 e, blue light 162 has aGaussian wavelength spectrum 187 b between about 425 nm and 475 nm. Inthis way, lighting system 100 a is capable of providing a wavelengthspectrum which corresponds to the action spectrum of β-carotene whenlighting system 100 a includes LEDs capable of emitting blue-violetlight 170 and blue light 162.

As mentioned above, the intensity of the light provided by the differenttypes of LEDs of lighting system 100 a are adjustable relative to eachother. In one embodiment, inputs 110 and 111 correspond to switches sothat the intensity of blue-violet light 170 provided by LED sub-array120 is adjusted by adjusting the number of LEDs 120 a. Further, theintensity of blue light 162 provided by LED sub-array 121 is adjusted byadjusting the number of LEDs 121 a.

In another embodiment, input 110 includes potentiometer 137 a, so thatthe intensity of blue-violet light 170 provided by LED sub-array 120 isadjusted by adjusting potentiometer 137 a, as described in more detailabove. Further, input 111 includes potentiometer 137 b, so that theintensity of blue light 162 provided by LED sub-array 121 is adjusted byadjusting potentiometer 137 b, as described in more detail above. Itshould be noted that the relative intensities of blue-violet light 170and blue light 162 can be adjusted relative to each other in response toadjusting potentiometers 136 a and 136 b. It should also be noted thatthe physiological activity of β-carotene can be driven in response tothe light from one type of LED, as will be discussed in more detailpresently.

In the situation of FIG. 4 f, input 110 provides signal S_(Input1) toLED driver circuit 140, and LED driver circuit 140 provides signalS_(Output1) to LED sub-array 120, wherein LED sub-array 120 includes LED120 a. In this particular example, LED 120 a is an LED that emitsblue-violet light 170 when activated. As shown in FIG. 4 f, blue-violetlight 170 has a Gaussian wavelength spectrum 188 a between about 400 nmand 500 nm. In this way, LED 120 a provides blue-violet light 170 whichhas a broader spectrum than the spectrum of violet light 161. FIG. 4 e,Further, LED 120 a provides blue-violet light 170 which has a broaderspectrum than the spectrum of blue light 162 FIG. 4 e. As mentionedabove, the wavelength distribution of light provided by an LED can bemade broader and narrower in many different ways, such as by choosingthe semiconductor material composition of the LED.

Further, in this situation, input 111 provides input signal S_(Input2)to LED driver circuit 141, and LED driver circuit 141 provides outputsignal S_(Output2) to LED sub-array 121, wherein LED sub-array 121includes LED 121 a. In this particular example, LED 121 a is deactivatedin response to receiving output signal S_(Output2). In this way, thephysiological activity of β-carotene is driven in response to the lightfrom one type of LED.

In one embodiment, inputs 110 and 111 correspond to switches so that theintensity of blue-violet light 170 provided by LED sub-array 120 isadjusted by adjusting the number of LEDs 120 a. Further, the intensityof blue light 162 provided by LED sub-array 121 is adjusted bydeactivating LEDs 121 a.

In another embodiment, input 110 includes potentiometer 137 a, so thatthe intensity of blue-violet light 170 provided by LED sub-array 120 isadjusted by adjusting potentiometer 137 a, as described in more detailabove. Further, input 111 includes potentiometer 137 b, so that theintensity of light provided by LED sub-array 121 is adjusted byadjusting potentiometer 137 b so that output signal S_(Output2)deactivates LEDs 121 a.

FIG. 4 g is a graph of wavelength spectrum 189 of light provided bylighting system 100 a. Action spectrum corresponding to pelargonin(Perlargonidin-3,5-diglucoside) is also shown in FIG. 4 g. In FIG. 4 g,wavelength spectrum 189 corresponds to the intensity of light versuswavelength (nm), as discussed above with wavelength spectrum 180.

In the situation of FIG. 4 g, input 110 provides signal S_(Input1) toLED driver circuit 140, and LED driver circuit 140 provides signalS_(Output1) LED sub-array 120, wherein LED sub-array 120 includes LED120 a. In this particular example, LED 120 a is an LED that emitsblue-green light 171 when activated. As shown in FIG. 4 g, blue-greenlight 171 has a Gaussian wavelength spectrum 189 a between about 450 nmand 550 nm. In this way, LED 120 a provides blue-green light 171 whichhas a broader spectrum than the spectrum of blue light 162 FIG. 4 c. Asmentioned above, the wavelength distribution of light provided by an LEDcan be made broader and narrower in many different ways, such as bychoosing the semiconductor material composition of the LED.

Further, in this situation, input 111 provides input signal S_(Input2)to LED driver circuit 141, and LED driver circuit 141 provides outputsignal S_(Output2) to LED sub-array 121, wherein LED sub-array 121includes LED 121 a. In this particular example, LED 121 a is deactivatedin response to receiving output signal S_(Output2). In this way, thephysiological activity of pelargonin is driven in response to the lightfrom one type of LED.

In one embodiment, inputs 110 and 111 correspond to switches so that theintensity of blue-green light 171 provided by LED sub-array 120 isadjusted by adjusting the number of LEDs 120 a. Further, the intensityof blue-green light 171 provided by LED sub-array 121 is adjusted bydeactivating LEDs 121 a.

In another embodiment, input 110 includes potentiometer 137 a, so thatthe intensity of light provided by LED sub-array 120 is adjusted byadjusting potentiometer 137 a, as described in more detail above.Further, input 111 includes potentiometer 137 b, so that the intensityof light provided by LED sub-array 121 is adjusted by adjustingpotentiometer 137 b so that output signal S_(Output2) deactivates LEDs121 a.

It should be noted that the broadness of the wavelength spectra ofblue-green light 171 can be chosen by choosing the semiconductormaterial of LEDs 120 a, as discussed above with FIG. 4 f. Further, itshould be noted that, in some embodiments, LEDs 121 a emit green light163 and are activated so that green light 163 is mixed with blue-greenlight 171. In this way, wavelength spectrum 189 corresponds to thewavelength spectra of two different types of LEDs, as discussed abovewith FIG. 4 e.

FIG. 4 h is a graph of wavelength spectrum 190 of light provided bylighting system 100 a, Action spectrum corresponding to phycocyanin isalso shown in FIG. 4 h. In FIG. 4 h, wavelength spectrum 190 correspondsto the intensity of light versus wavelength (nm), as discussed abovewith wavelength spectrum 180.

In the situation of FIG. 4 h, input 110 provides signal S_(Input1) toLED driver circuit 140, and LED driver circuit 140 provides signalS_(Output1) to LED sub-array 120, wherein LED sub-array 120 includes LED120 a. In this particular example, LED 120 a is an LED that emitsyellow-orange light 172 when activated. As shown in FIG. 4 h,yellow-orange light 172 has a Gaussian wavelength spectrum 189 a betweenabout 575 nm and 625 nm.

Further, in this situation, input 111 provides input signal S_(Input2)to LED driver circuit 141, and LED driver circuit 141 provides outputsignal S_(Output2) to LED sub-array 121, wherein LED sub-array 121includes LED 121 a. In this particular example, LED 121 a is deactivatedin response to receiving output signal S_(Output2). In this way, thephysiological activity of pelargonin is driven in response to the lightfrom one type of LED.

In one embodiment inputs 110 and 111 correspond to switches so that theintensity of yellow-orange light 172 provided by LED sub-array 120 isadjusted by adjusting the number of LEDs 120 a. Further, the intensityof yellow-orange light 172 provided by LED sub-array 121 is adjusted bydeactivating LEDs 121 a.

In another embodiment, input 110 includes potentiometer 137 a, so thatthe intensity of yellow-orange light 172 provided by LED sub-array 120is adjusted by adjusting potentiometer 137 a, as described in moredetail above. Further, input 111 includes potentiometer 137 b, so thatthe intensity of light provided by LED sub-array 121 is adjusted byadjusting potentiometer 137 b so that output signal S_(Output2)deactivates LEDs 121 a. It should be noted that the broadness of thewavelength spectra of yellow-orange light 172 can be chosen by choosingthe semiconductor material of LEDs 120 a, as discussed above with FIG. 4f.

FIG. 4 i is a graph of wavelength spectrum 191 of light provided bylighting system 100 a. Action spectrum corresponding to phycoerythrin isalso shown in FIG. 4 i. In FIG. 4 i, wavelength spectrum 191 correspondsto the intensity of light versus wavelength (nm), as discussed abovewith wavelength spectrum 180.

In the situation of FIG. 4 i, input 110 provides signal S_(Input1) toLED driver circuit 140, and LED driver circuit 140 provides signalS_(Output1) to LED sub-array 120, wherein LED sub-array 120 includes LED120 a. In this particular example, LED 120 a is an LED that emitsblue-green light 171 when activated. As shown in FIG. 4 i, blue-greenlight 171 has a Gaussian wavelength spectrum 181 a between about 475 nmand 550 nm.

Further, in this situation, input 111 provides input signal S_(Input2)to LED driver circuit 141, and LED driver circuit 141 provides outputsignal S_(Output2) to LED sub-array 121, wherein LED sub-array 121includes LED 121 a. In this particular example, LED 121 a emits greenlight 163 when activated. As shown in FIG. 4 i, green light 163 has aGaussian wavelength spectrum 191 b between about 500 nm and 575 nm. Inthis way, the physiological activity of phycoerythrin is driven inresponse to the light from two types of LEDs.

In one embodiment, inputs 110 and 111 correspond to switches so that theintensity of blue-green light 171 provided by LED sub-array 120 isadjusted by adjusting the number of LEDs 120 a. Further, the intensityof green light 163 provided by LED sub-array 121 is adjusted byadjusting the number of LEDs 121 a.

In another embodiment, input 110 includes potentiometer 137 a, so thatthe intensity of blue-green light 171 provided by LED sub-array 120 isadjusted by adjusting potentiometer 137 a, as described in more detailabove. Further, input 111 includes potentiometer 137 b, so that theintensity of green light 163 provided by LED sub-array 121 is adjustedby adjusting potentiometer 137 b, as described in more detail above. Itshould be noted that the broadness of the wavelength spectra ofblue-green light 171 and/or green light 163 can be chosen by choosingthe semiconductor material of LEDs 120 a and 121 a, respectively, asdiscussed in more detail above.

As mentioned above, the lighting system can include one or more LEDsub-arrays, which include different types of LEDs. As will be discussedin more detail presently, the type of LEDs of the sub-arrays can bechosen so that the lighting system can provide a desired wavelengthspectrum between UV light and IR light, which is useful to drive thephysiological activity of a plant.

FIGS. 5 a and 5 b are bottom and top perspective views, respectively, ofa lighting system 100 b. In this embodiment, lighting system 100 bincludes inputs 110, 111, 112, 113 and 114 (FIG. 5 b) operativelycoupled to LED arrays 102 and 103 through LED controller 130 (notshown). As discussed in more detail below, LED arrays 102 and 103 eachinclude LED sub-arrays connected to inputs 110-114. The LED sub-arraysof LED arrays 102 and 103 each include a plurality of LEDs, as will bediscussed in more detail with FIGS. 5 f and 5 g. The LEDs of arrays 102and 103 can be of many different types, such as those mentioned above.

LED arrays 102 and 103 are spaced apart from each other by a distance L(FIG. 5 b) so that lighting system 100 b provides a desired intensity oflight away from. LED arrays 102 and 103. LED arrays 102 and 103 arespaced apart from each other by distance L so that lighting system 100 bcan be more effectively cooled, as will be discussed in more detailbelow. It should be noted that, in this embodiment, LED arrays 102 and103 include the same number of LEDs. However, in other embodiments, LEDarrays 102 and 103 can include different numbers of LEDs. For example,in one embodiment, LED array 102 includes twenty five LEDs and LED array103 includes twenty six LEDs.

In this embodiment, lighting system 100 b includes a lighting systemhousing 101 which houses LED arrays 102 and 103. FIGS. 5 c and 5 d aretop and back perspective views of lighting system 100 b with and withoutlighting system housing 101, respectively. FIG. 5 e is a frontperspective view of lighting system 100 b without lighting systemhousing 101. As shown in FIGS. 5 c and 5 d, lighting system 100 bincludes an on/off switch 109 operatively coupled with LED controller130. On/off switch 109 is for turning LED controller 130 on and off.

As shown in FIGS. 5 a, 5 b, 5 d and 5 e, lighting system 100 b includesfens 104 a and 104 b which provide cooling. For example, fans 104 a and104 b can cool LED controller 130 (not shown) and LED arrays 102 and103. Fans 104 a and 104 b can be positioned at many different locationsof lighting system 100 b. In this embodiment, fans 104 a and 104 b arepositioned between LED arrays 102 and 103.

As shown in FIGS. 5 d and 5 c, lighting system 100 includes heatsinks105 a and 105 b which provide cooling for LED arrays 102 and 103,respectively. Heatsinks 105 a and 105 b also provide cooling for LEDcontroller 130. As mentioned above, LED arrays 102 and 103 are spacedapart from each other by distance L, which allows LED arrays 102 and 103to be more effectively cooled by fans 104 a and 104 b, and correspondingheatsinks 105 a and 105 b.

FIG. 5 f is a front view of LED array 102 of lighting system 100 b,wherein LED array 102 includes LED sub-arrays 120, 121, 122, 123 and 124carried by LED array support structure 106 a. LED array 102 generallyincludes one or more LED sub-arrays, but it includes five LED sub-arraysin this embodiment for illustrative purposes. An embodiment in which LEDarray 102 includes two LED sub-arrays is discussed in more detail above.

In this embodiment, LED sub-arrays 120, 121, 122, 123 and 124 eachinclude five LEDs for illustrative purposes so that LED array 102includes twenty five LEDs. However, as discussed in more detail abovewith FIG. 1 c, LED array 102 includes two or more sub-arrays LEDs, andthe LED sub-arrays generally include one or more LEDs.

In this embodiment, LED sub-array 120 includes LEDs 120 a, 120 b, 120 c,120 d and 120 e, and LED sub-array 121 includes LEDs 121 a, 121 b, 121c, 121 d and 121 e. LED sub-array 122 includes LEDs 122 a, 122 b, 122 c,122 d and 122 e, and LED sub-array 123 includes LEDs 123 a, 123 b, 123c, 123 d and 123 e. Further, LED sub-array 124 includes LEDs 124 a, 124b, 124 c, 124 d and 124 e. The light emitting diodes included with LEDarray 102 can emit many different colors of light in response to outputsignals received from LED controller 130, as will be discussed in moredetail below with FIGS. 9 a-9 f.

FIG. 5 g is a front view of LED array 103 of lighting system 100 b,wherein LED array 103 includes LED sub-arrays 125, 126, 127, 128 and 129carried by LED array support structure 106 b. LED array 103 generallyincludes one or more LED sub-arrays, but it includes five LED sub-arraysin this embodiment for illustrative purposes. An embodiment in which LEDarray 103 includes two LED sub-arrays is discussed in more detail above.

In this embodiment, LED sub-arrays 125, 126, 127, 128 and 129 eachinclude five LEDs for illustrative purposes so that LED array 103includes twenty five LEDs. However, as discussed in more detail abovewith FIG. 1 c, LED array 103 includes two or more LEDs, and LEDsub-arrays generally include one or more LEDs.

In this embodiment, LED sub-array 125 includes LEDs 125 a, 125 b, 125 c,125 d and 125 e, and LED sub-array 126 includes LEDs 126 a, 126 b, 126c, 126 d and 126 e. LED sub-array 127 includes LEDs 127 a, 127 b, 127 c,127 d and 127 e, and LED sub-array 128 includes LEDs 128 a, 128 b, 128c, 128 d and 128 e. Further, LED sub-array 129 includes LEDs 129 a, 129b, 129 c, 129 d and 129 e. The light emitting diodes included with LEDarray 103 can emit many different colors of light in response to outputsignals received front LED controller 130, as will be discussed in moredetail below with FIGS. 9 a-9 f.

In this particular embodiment, LED sub-arrays 120 and 125 include LEDswhich are capable of emitting UV light 160. Hence, LEDs 120 a-120 e andLEDs 125 a-125 e are capable of emitting UV light 160. In someembodiments, UV light 160 has a wavelength between about 300 and 380 nm.In other embodiments, IR light 167 has a wavelength between about 350and 380 nm.

LED sub-arrays 121 and 126 include LEDs which are capable of emittingblue light 162. Hence, LEDs 121 a-121 e and LEDs 126 a-126 e are capableof emitting blue light 162. LED sub-arrays 122 and 127 include LEDswhich are capable of emitting green light 163. Hence, LEDs 122 a-122 eand LEDs 127 a-127 e are capable of emitting green light 163. LEDsub-arrays 123 and 128 include LEDs which are capable of emitting redlight 166. Hence, LEDs 123 a-123 e and LEDs 128 a-128 e are capable ofemitting red light 166. LED sub-arrays 124 and 129 include LEDs whichare capable of emitting IR light 167. Hence, LEDs 124 a-124 e and LEDs129 a-129 e are capable of emitting IR light 167. In some embodiments,IR light 167 has a wavelength between about 750 and 825 nm. In otherembodiments, IR light 167 has a wavelength between about 750 and 900 nm.

FIGS. 6 a and 6 b are block diagram of lighting system 100 b, whichincludes inputs 110-114 operatively coupled to LED arrays 102 and 103through LED controller 130, wherein LED controller 130 includes LEDsub-controllers 131 and 132. In this embodiment, and as shown in FIG. 6a. LED sub-controller 131 is operatively coupled to inputs 110, 111,112, 113 and 114, as well as to LED array 102. In this embodiment LEDsub-controller 131 includes LED driver circuits 140, 141, 142, 143 and144 operatively coupled to LED sub-arrays 120, 121, 122, 123 and 124,respectively. Further, inputs 110, 111, 112, 113 and 114 are operativelycoupled with LED driver circuits 140, 141, 142, 143 and 144,respectively.

In operation, input 110 provides input signal S_(Input1) to LED drivercircuit 140 and, in response, LED driver circuit 140 provides outputsignal S_(Output1) LED sub-array 120. Further, input 111 provides inputsignal S_(Input2) to LED driver circuit 141 and, in response, LED drivercircuit 141 provides output signal S_(Output2) to LED sub-array 121.Input 112 provides an input signal S_(Input3) to LED driver circuit 141and, in response, LED driver circuit 141 provides an output signalS_(Output3) to LED sub-array 122. Input 113 provides an input signalS_(Input4) to LED driver circuit 141 and, in response, LED drivercircuit 141 provides an output signal S_(Output4) to LED sub-array 123.Input 114 provides an input signal S_(Input5) to LED driver circuit 141and, in response, LED driver circuit 141 provides an output signalS_(Output5) to LED sub-array 124. In this way, inputs 110-114 areoperatively coupled to LED array 102 through LED sub-controller 131.

In this embodiment, and as shown in FIG. 6 b, LED sub-controller 132 isoperatively coupled to inputs 110, 111, 112, 113 and 114, as well as toLED array 103. In this embodiment, LED sub-controller 132 includes LEDdriver circuits 145, 146, 147, 148 and 149 operatively coupled to LEDsub-arrays 125, 126, 127, 128 and 129, respectively. Further, inputs110, 111, 112, 113 and 114 are operatively coupled with LED drivercircuits 145, 146, 147, 148 and 149, respectively.

In operation, input 110 provides input signal S_(Input1) to LED drivercircuit 145 and, in response, LED driver circuit 145 provides outputsignal S_(Output1) to LED sub-array 125, Further, input 111 providesinput signal S_(Input2) to LED driver circuit 146 and, in response, LEDdriver circuit 146 provides output signal S_(Output2) to LED sub-array126. Input 112 provides input signal S_(Input3) to LED driver circuit147 and, in response, LED driver circuit 147 provides output signalS_(Output3) to LED sub-array 127. Input 113 provides input signalS_(Input4) to LED driver circuit 148 and, in response, LED drivercircuit 148 provides output signal S_(Output4) to LED sub-array 128.Input 114 provides input signal S_(Input5) to LED driver circuit 149and, in response, LED driver circuit 149 provides output signalS_(Output5) to LED sub-array 129. In this way, inputs 110-114 areoperatively coupled to LED array 103 through LED sub-controller 132.

In some embodiments, inputs 110-114 each, operate as a switch which, isrepeatably moveable between active and deactive conditions, as describedin more detail above with FIGS. 1 a, 1 b and 1 c. However, in thisembodiment, inputs 110-114 include potentiometers, as will be discussedin more detail below.

FIG. 7 a is a schematic diagram of input 110 operatively coupled to LEDsub-array 120 through LED driver circuit 140, wherein input 110 operatesas a potentiometer. In this embodiment, input 110 includes potentiometer137 a, which is connected between power terminal 108 a and currentreturn 136. The output of potentiometer 137 a is connected to LED drivercircuit 140, which includes LED driver circuit chip 150, so that LEDdriver circuit 140 receives input signal S_(Input1). LED driver circuitchip 150 provides output signal S_(Output1) to LED sub-array 120 (FIG. 6a) in response to receiving input signal S_(Input1) from input 110. Inparticular, LED driver circuit chip 150 provides output signalS_(Output1) to LEDs 120 a-120 e. LEDs 120 a-120 e emit UV light 160 inresponse to being activated by output signal S_(Output1). Further, LEDs120 a-120 e do not emit UV light 160 in response to being deactivated byoutput signal S_(Output1).

It should be noted that more information regarding LED driver circuitsand LED driver circuit chips, as well as the connections of thecomponents of lighting system 100 a, is provided in more detail abovewith the discussion of FIGS. 1 a, 1 b and 1 c, as well as with thediscussion of FIGS. 2 a and 2 b.

FIG. 7 b is a schematic diagram of input 111 operatively coupled to LEDsub-array 121 through LED driver circuit 141, wherein input 111 operatesas a potentiometer. In this embodiment, input 111 includes potentiometer137 b, which is connected between power terminal 108 a and currentreturn 136. The output of potentiometer 137 b is connected to LED drivercircuit 141, which includes LED driver circuit chip 151, so that LEDdriver circuit 141 receives input signal S_(Input2). LED driver circuitchip 151 provides output signal S_(Output2) to LED sub-array 121 (FIG. 6a) in response to receiving input signal S_(Input2) from input 111. Inparticular, LED driver circuit chip 151 provides output signalS_(Output2) to LEDs 121 a-121 e. LEDs 121 a-121 e emit blue light 162 inresponse to being activated by output signal S_(Output2). Further, LEDs121 a-121 e do not emit blue light 162 in response to being deactivatedby output signal S_(Output2).

FIG. 7 c is a schematic diagram of input 112 operatively coupled to LEDsub-array 122 through LED driver circuit 142, wherein input 112 operatesas a potentiometer. In this embodiment, input 112 includes apotentiometer 137 c, which is connected between power terminal 108 a andcurrent return 136. The output of potentiometer 137 c is connected toLED driver circuit 142, which includes an LED driver circuit chip 152,so that LED driver circuit 142 receives input signal S_(Input3). LEDdriver circuit chip 152 provides output signal S_(Output3) to LEDsub-array 122 (FIG. 6 a) in response to receiving input signalS_(Input3) front input 112. In particular, LED driver circuit chip 152provides output signal S_(Output3) to LEDs 122 a-122 e. LEDs 122 a-122 eemit green light 163 in response to being activated by output signalS_(Output3). Further, LEDs 122 a-122 e do not emit green light 163 inresponse to being deactivated by output signal S_(Output3).

FIG. 7 d is a schematic diagram of input 113 operatively coupled to LEDsub-array 123 through LED driver circuit 143, wherein input 113 operatesas a potentiometer. In this embodiment, input 113 includes apotentiometer 137 d, which is connected between power terminal 108 a andcurrent return 136. The output of potentiometer 137 d is connected toLED driver circuit 143, which includes an LED driver circuit chip 153,so that LED driver circuit 143 receives input signal S_(Input4). LEDdriver circuit chip 153 provides output signal S_(Output4) to LEDsub-array 123 (FIG. 6 a) in response to receiving input signalS_(Input4) from input 113. In particular, LED driver circuit chip 153provides output signal S_(Output4) to LEDs 123 a-123 e. LEDs 123 a-123 eemit red light 166 in response to being activated by output signalS_(Output4). Further, LEDs 123 a-123 e do not emit red light 166 inresponse to being deactivated by output signal S_(Output4).

FIG. 7 e is a schematic diagram of input 114 operatively coupled to LEDsub-array 124 through LED driver circuit 144, wherein, input 114operates as a potentiometer. In this embodiment, input 114 includes apotentiometer 137 e, which is connected between power terminal 108 a andcurrent return 136. The output of potentiometer 137 e is connected toLED driver circuit 144, which includes an LED driver circuit chip 154,so that LED driver circuit 144 receives input signal S_(Input5). LEDdriver circuit chip 154 provides output signal S_(Output5) to LEDsub-array 124 (FIG. 6 a) in response to receiving input signalS_(Input5) from input 114. In particular, LED driver circuit chip 154provides output signal S_(Output5) to LEDs 124 a-124 e. LEDs 124 a-124 eemit IR light 167 in response to being activated by output signalS_(Output5). Further, LEDs 124 a-124 e do not emit IR light 167 inresponse to being deactivated by output signal S_(Output5).

FIG. 8 a is a schematic diagram of input 110 operatively coupled to LEDsub-array 125 through LED driver circuit 145. As mentioned above, input110 includes potentiometer 137 a, which is connected between powerterminal 108 a and current return 136. In this embodiment, the output ofpotentiometer 137 a is connected to LED driver circuit 145, whichincludes an LED driver circuit chip 155, so that LED driver circuit 145receives input signal S_(Input1). LED driver circuit chip 155 providesoutput signal S_(Output1) to LED sub-array 125 (FIG. 6 b) in response toreceiving input signal S_(Input1) from input 110. In particular, LEDdriver circuit chip 155 provides output signal S_(Output1) LEDs 125a-125 e. LEDs 125 a-125 e emit UV light 160 in response to beingactivated by output signal S_(Output1). Further, LEDs 125 a-125 e do notemit UV light 160 in response to being deactivated by output signalS_(Output1).

FIG. 8 b is a schematic diagram of input 111 operatively coupled to LEDsub-array 126 through LED driver circuit 146. As mentioned above, input111 includes potentiometer 137 b, which is connected between powerterminal 108 a and current return 136. In this embodiment, the output ofpotentiometer 137 b is connected to LED driver circuit 146, whichincludes an LED driver circuit chip 156, so that LED driver circuit 146receives input signal S_(Input2). LED driver circuit chip 156 providesoutput signal S_(Output2) to LED sub-array 126 (FIG. 6 b) in response toreceiving input signal S_(Input2) from input 111. In particular, LEDdriver circuit chip 156 provides output signal S_(Output2) to LEDs 126a-126 e. LEDs 126 a-126 e emit blue light 162 in response to beingactivated by output signal S_(Output2). Further, LEDs 126 a-126 e do notemit blue light 162 in response to being deactivated by output signalS_(Output2).

FIG. 8 c is a schematic diagram of input 112 operatively coupled to LEDsub-array 127 through LED driver circuit 147. As mentioned above, input112 includes potentiometer 137 c, which is connected between powerterminal 108 a and current return 136. In this embodiment, the output ofpotentiometer 137 c is connected to LED driver circuit 147, whichincludes an LED driver circuit chip 157, so that LED driver circuit 147receives input signal S_(Input3). LED driver circuit chip 157 providesoutput signal S_(Output3) to LED sub-array 127 (FIG. 6 b) in response toreceiving input signal S_(Input3) from input 112. In particular, LEDdriver circuit chip 157 provides output signal S_(Output3) to LEDs 127a-127 e. LEDs 127 a-1272 e emit green light 163 in response to beingactivated by output signal S_(Output3). Further, LEDs 127 a-127 e do notemit green light 163 in response to being deactivated by output signalS_(Output3).

FIG. 8 d is a schematic diagram of input 113 operatively coupled to LEDsub-array 128 through LED driver circuit 148. As mentioned above, input113 includes potentiometer 137 d, which is connected between powerterminal 108 a and current return 136. In this embodiment, the output ofpotentiometer 137 d is connected to LED driver circuit 148, winchincludes an LED driver circuit chip 158, so that LED driver circuit 148receives input signal S_(Input4). LED driver circuit chip 158 providesoutput signal S_(Output4) to LED sub-array 128 (FIG. 6 b) in response toreceiving input signal S_(Input4) from input 113. In particular, LEDdriver circuit chip 158 provides output signal S_(Output4) to LEDs 127a-127 e. LEDs 127 a-127 e emit red light 166 in response to beingactivated by output signal S_(Output4). Further, LEDs 127 a-127 e do notemit red light 166 in response to being deactivated by output signalS_(Output4).

FIG. 8 e is a schematic diagram of input 114 operatively coupled to LEDsub-array 129 through LED driver circuit 149. As mentioned above, input114 includes potentiometer 137 e, which is connected between powerterminal 108 a and current return 136. In this embodiment, the output ofpotentiometer 137 e is connected to LED driver circuit 149, whichincludes an LED driver circuit chip 159, so that LED driver circuit 149receives input signal S_(Input5). LED driver circuit chip 159 providesoutput signal S_(Output5) to LED sub-array 129 (FIG. 6 b) in response toreceiving input signal S_(Input5) from input 114. In particular, LEDdriver circuit chip 159 provides output signal S_(Output5) to LEDs 129a-129 e. LEDs 129 a-129 c emit IR light 167 in response to beingactivated by output signal S_(Output5). Further, LEDs 129 a-129 e do notemit IR light 167 in response to being deactivated by output signalS_(Output5).

As mentioned above, the light emitting diodes included with LED arrays102 and 103 can emit many different colors of light in response tooutput signals received from LED controller 130, as will be discussed inmore detail presently.

FIG. 9 a is a graph of a wavelength spectrum 192 of light provided bylighting system 100 b, wherein wavelength spectrum 192 includes colormixing. In FIG. 9 a, wavelength spectrum 192 corresponds to theintensity of light versus wavelength (nm), as discussed above withwavelength spectrum 180.

As mentioned above with FIGS. 7 a and 8 a, input 110 includespotentiometer 137 a. In some situations, potentiometer 137 a is adjustedso the power of input signal S_(Input1) and output signal S_(Output1)are decreased. The intensity of UV light 160 decreases, as indicated bywavelength spectrum 192 b, in response to decreasing the power of inputsignal S_(Input1) and output signal S_(Output1) with potentiometer 137a.

In some situations, potentiometer 137 a is adjusted so the power ofinput signal S_(Input1) and output signal S_(Output1) are increased. Theintensity of UV light 160 increases, as indicated by wavelength spectrum192 c, in response to increasing the power of input signal S_(Input1)and output signal S_(Output1) with potentiometer 137 a.

As mentioned above with FIGS. 7 b and 8 b, input 111 includespotentiometer 137 b. In some situations, potentiometer 137 b is adjustedso the power of input signal S_(Input2) and output signal S_(Output2)are decreased. The intensity of blue light 162 decreases, as indicatedby wavelength spectrum 193 b, in response to decreasing the power ofinput signal S_(Input2) and output signal S_(Output2) with potentiometer137 b.

In some situations, potentiometer 137 b is adjusted so the power ofinput signal S_(Input2) and output signal S_(Output2) are increased. Theintensity of blue light 162 increases, as indicated by wavelengthspectrum 193 c, in response to increasing the power of input signalS_(Input2) and output signal S_(Output2) with potentiometer 137 b.

As mentioned above with FIGS. 7 c and 8 c, input 112 includespotentiometer 137 c. In some situations, potentiometer 137 c isadjusted, so the power of input signal S_(Input3) and output signalS_(Output3) are decreased. The intensity of green light 163 decreases,as indicated by wavelength spectrum 194 b, in response to decreasing thepower of input signal S_(Input3) and output signal S_(Output3) withpotentiometer 137 c.

In some situations, potentiometer 137 c is adjusted so the power ofinput signal S_(Input3) and output signal S_(Output3) are increased. Theintensity of green light 163 increases, as indicated by wavelengthspectrum 194 c, in response to increasing the power of input signalS_(Input3) and output signal S_(Output3) with potentiometer 137 c.

As mentioned above with FIGS. 7 d and 8 d, input 113 includespotentiometer 137 d. In some situations, potentiometer 137 d is adjustedso the power of input signal S_(Input4) and output signal S_(Output4)are decreased. The intensity of red light 166 decreases, as indicated bywavelength spectrum 195 b, in response to decreasing the power of inputsignal S_(Input4) and output signal S_(Output4) with potentiometer 137d.

In some situations, potentiometer 137 d is adjusted so the power ofinput signal S_(Input4) and output signal S_(Output4) are increased. Theintensity of red light 166 increases, as indicated by wavelengthspectrum 195 d, in response to increasing the power of input signalS_(Input4) and output signal S_(Output4) with potentiometer 137 d.

As mentioned above with FIGS. 7 c and 8 e, input 114 includespotentiometer 137 e. In some situations, potentiometer 137 e is adjustedso the power of input signal S_(Input5) and output signal S_(Output5)are decreased. The intensity of IR light 167 decreases, as indicated bywavelength spectrum 196 b, in response to decreasing the power of inputsignal S_(Input5) and output signal S_(Output5) with potentiometer 137e.

In some situations, potentiometer 137 e is adjusted so the power ofinput signal S_(Input5) and output signal S_(Output5) are increased. Theintensity of IR light 167 increases, as indicated by wavelength spectrum195 e, in response to increasing the power of input signal S_(Input5)and output signal S_(Output5) with potentiometer 137 e. In this way, thelight emitting diodes included with LED arrays 102 and 103 emitdifferent colors of light in response to output signals received fromLED controller 130.

FIG. 9 b is a graph of a wavelength spectrum 200 of light provided bylighting system 100 b, wherein wavelength spectrum 200 includes colormixing. In FIG. 9 b, wavelength spectrum 200 corresponds to theintensity of light versus wavelength (nm), as discussed above withwavelength spectrum 180.

In this example, potentiometer 137 a is adjusted so the power of inputsignal S_(Input1) and output signal S_(Output1) are adjusted, and theintensity of UV light 160 is driven to zero. In this example,potentiometer 137 b is adjusted so the power of input signal S_(Input2)and output signal S_(Output2) are adjusted, and the intensity of bluelight 162 is driven to that indicated by wavelength spectrum 193 a. Inthis example, potentiometer 137 c is adjusted so the power of inputsignal S_(Input3) and output signal S_(Output3) are adjusted, and theintensity of green light 163 is driven to that indicated by wavelengthspectrum 194 b.

In this example, potentiometer 137 d is adjusted so the power of inputsignal S_(Input4) and output signal S_(Output4) are adjusted, and theintensity of red light 166 is driven to that indicated by wavelengthspectrum 195 a. In this example, potentiometer 137 e is adjusted so thepower of input signal S_(Input5) and output signal S_(Output5) areadjusted, and the intensity of IR light 167 is driven to that indicatedby wavelength spectrum 196 c.

FIG. 9 c is a graph of a wavelength spectrum 201 of light provided bylighting system 100 b, wherein wavelength spectrum 201 includes colormixing. In FIG. 9 c, wavelength spectrum 201 corresponds to theintensity of light versus wavelength (nm), as discussed above withwavelength spectrum 180.

In this example, potentiometer 137 a is adjusted so the power of inputsignal S_(Input1) and output signal S_(Output1) are adjusted, and theintensity of UV light 160 is driven to zero. In this example,potentiometer 137 b is adjusted so the power of input signal S_(Input2)and output signal S_(Output2) are adjusted, and the intensity of bluelight 162 is driven to that indicated by wavelength spectrum 193 a. Inthis example, potentiometer 137 c is adjusted so the power of inputsignal S_(Input3) and output signal S_(Output3) are adjusted, and theintensity of green light 163 is driven to that indicated by wavelengthspectrum 194 c.

In this example, potentiometer 137 d is adjusted so the power of inputsignal S_(Input4) and output signal S_(Output4) are adjusted, and theintensity of red light 166 is driven to that indicated by wavelengthspectrum 195 b. In this example, potentiometer 137 e is adjusted so thepower of input signal and output signal S_(Output5) are adjusted, andthe intensity of IR light 167 is driven to that indicated by wavelengthspectrum 196 b.

It should be noted that the desired mixture of light provided bylighting system 100 b can be chosen to correspond to an action spectrumof a physiological activity of a plant, as will be discussed in moredetail presently.

FIG. 9 d is a graph of a wavelength spectrum 202 of light provided bylighting system 100 b, wherein wavelength spectrum 202 includes colormixing. Action spectrum corresponding to chlorophyll a is also shown inFIG. 94. In FIG. 9 d, wavelength spectrum 202 and the action spectrumcorresponding to chlorophyll a correspond to the intensity of lightversus wavelength (nm).

In this example, potentiometer 137 a is adjusted so the power of inputsignal S_(Input1) and output signal S_(Output1) are adjusted, and theintensity of UV light 160 is driven to zero. In this example,potentiometer 137 b is adjusted so the power of input signal S_(Input2)and output signal S_(Output2) are adjusted, and the intensity of bluelight 162 is driven to that indicated by wavelength spectrum 193 a. Inthis example, potentiometer 137 c is adjusted so the power of inputsignal S_(Input3) and output signal S_(Output3) are adjusted, and theintensity of green light 163 is driven to zero.

In this example, potentiometer 137 d is adjusted so the power of inputsignal S_(Input4) and output signal S_(Output4) are adjusted, and theintensity of red light 166 is driven to that indicated by wavelengthspectrum 195 a. In this example, potentiometer 137 e is adjusted so thepower of input signal S_(Input5) and output signal S_(Output5) areadjusted, and the intensity of IR light 167 is driven to zero. In thisway, the desired mixture of light provided by lighting system 100 b ischosen to correspond to the action spectrum corresponding to chlorophylla.

FIG. 9 e is a graph of a wavelength spectrum 203 of light provided bylighting system 100 b, wherein wavelength spectrum 203 includes colormixing. Action spectrum corresponding to α-carotene is also shown inFIG. 9 e. In FIG. 9 e, wavelength spectrum 203 and the action spectrumcorresponding to α-carotene correspond to the intensity of light versuswavelength (nm).

It should be noted that, in this example, LED sub-arrays 120 and 125include LEDs which emit violet light 161 when activated, and do not emitviolet light 161 when deactivated. Hence, LEDs 120 a, 120 b, 120 c, 120d and 120 e in FIG. 7 a emit violet light 161 instead of UV light 160.Further, LEDs 125 a, 125 b, 125 c, 125 d and 125 e in FIG. 8 a emit bluelight 162 instead of UV light 160.

In this example, potentiometer 137 a is adjusted so the power of inputsignal S_(Input1) and output signal S_(Output1) are adjusted, and theintensity of violet light 161 is driven to that indicated by wavelengthspectrum 196 a. In this example, potentiometer 137 b is adjusted so thepower of input signal S_(Input2) and output signal S_(Output2) areadjusted, and the intensity of blue light 162 is driven to thatindicated by wavelength spectrum 193 a. In this example, potentiometer137 c is adjusted so the power of input signal S_(Input3) and outputsignal S_(Output3) are adjusted, and the intensity of green light 163 isdriven to zero.

In this example, potentiometer 137 d is adjusted so the power of inputsignal S_(Input4) and output signal S_(Output4) are adjusted, and theintensity of red light 166 is driven to zero. In this example,potentiometer 137 e is adjusted so the power of input signal S_(Input5)and output signal S_(Output5) are adjusted, and the intensity of IRlight 167 is driven to zero. In this way, the desired mixture of lightprovided by lighting system 100 b is chosen to correspond to the actionspectrum, corresponding to α-carotene.

FIG. 9 f is a graph of a wavelength spectrum 204 of light provided bylighting system 100 b, wherein wavelength spectrum 204 includes colormixing. Action spectrum corresponding to pelargonin is also shown inFIG. 9 f. In FIG. 9 f, wavelength spectrum 204 and the action spectrumcorresponding to pelargonin correspond to the intensity of light versuswavelength (nm).

It should be noted that, in this example, LED sub-arrays 120 and 125include LEDs which emit green light 163 when activated, and do not emitgreen light 163 when deactivated. Hence, LEDs 120 a, 120 b, 120 c, 120 dand 120 e in FIG. 7 a emit violet light 161 instead of UV light 160.Further, LEDs 125 a, 125 b, 125 c, 125 d and 125 e in FIG. 8 a emitgreen light 163 instead of UV light 160.

Further, in this example, LED sub-arrays 121 and 126 include LEDs whichemit blue-green light 171 when activated, and do not emit blue-greenlight 171 when deactivated. Hence, LEDs 121 a, 121 b, 121 c, 121 d and121 e in FIG. 7 b emit blue-green light 171 instead of blue light 162.Further, LEDs 126 a, 126 b, 126 c, 126 d and 126 e in FIG. 8 b emitblue-green light 171 instead of blue light 162.

In this example, potentiometer 137 a is adjusted so the power of inputsignal S_(Input1) and output signal S_(Output1) are adjusted, and theintensity of violet light 161 is driven to zero. In this example,potentiometer 137 b is adjusted so the power of input signal S_(Input2)and output signal S_(Output 2) are adjusted, and the intensity ofblue-green light 171 is driven to that indicated by wavelength spectrum197 a. In this example, potentiometer 137 c is adjusted so the power ofinput signal S_(Input3) and output signal S_(Output3) are adjusted, andthe intensity of green light 163 is driven to that indicated bywavelength spectrum 194 c.

In this example, potentiometer 137 d is adjusted so the power of inputsignal S_(Input4) and output signal S_(Output 4) are adjusted, and theintensity of red light 166 is driven to zero. In this example,potentiometer 137 e is adjusted so the power of input signal S_(Input5)and output signal S_(Output5) are adjusted, and the intensity of IRlight 167 is driven to zero. In this way, the desired mixture of lightprovided by lighting system 100 b is chosen to correspond to the actionspectrum corresponding to pelargonin.

It should be noted that the desired mixture of light provided bylighting system 100 b can be chosen to correspond to a wavelengthspectrum of sunlight, as will be discussed in more detail presently.

FIG. 9 g is a graph of a wavelength spectrum 205 of light provided bylighting system 100 b, wherein wavelength spectrum 205 includes colormixing. A wavelength spectrum 197 corresponding to sunlight is alsoshown in FIG. 9 g, in FIG. 9 g, wavelength spectra 197 and 205correspond to the intensity of light versus wavelength (nm).

It should be noted that, in this example, LED sub-arrays 120 and 125include LEDs which emit UV light 160 when activated, and do not emit UVlight 160 when deactivated. Hence, LEDs 120 a, 120 b, 120 c, 120 d and120 e in FIG. 7 a emit UV light 160. Further, LEDs 125 a, 125 b, 125 c,125 d and 125 e in FIG. 8 a emit violet light 161.

Further, in this example, LED sub-arrays 121 and 126 include LEDs whichemit white light 168 when activated, and do not emit white light 168when deactivated. Hence, LEDs 121 a, 121 b, 121 c, 121 d and 121 e inFIG. 7 b emit white light 168. Further, LEDs 125 a, 125 b, 125 c, 125 dand 125 e in FIG. 8 b emit white light 168. A wavelength spectrum 197corresponding to white light 168 is also shown in FIG. 9 d. The LEDs ofLED sub-arrays 121 and 126 can emit white light 168 in many differentways. In this example, the LEDs of LED sub-arrays 121 and 126 emit whitelight 168 because they include phosphor coated LEDs, which emit bluelight. In another example, the LEDs of LED sub-arrays 121 and 126 emitwhite light 168 because they include phosphor coated LEDs, which emit UVlight.

In this example, potentiometer 137 a is adjusted so the power of inputsignal S_(Input1) and output signal S_(Output1) are adjusted, and theintensity of UV light 160 is driven to zero. In this example,potentiometer 137 b is adjusted so the power of input signal S_(Input2)and output signal S_(Output2) are adjusted, and the intensity of whitelight 168 is driven to that indicated by wavelength spectrum 197. Inthis example, potentiometer 137 c is adjusted so the power of inputsignal S_(Input3) and output signal S_(Output3) are adjusted, and theintensity of green light 163 is driven to that indicated by wavelengthspectrum 194 b.

In this example, potentiometer 137 d is adjusted so the power of inputsignal S_(Input4) and output signal S_(Output4) are adjusted, and theintensity of red light 166 is driven to that indicated by wavelengthspectrum 195 b. in this example, potentiometer 137 e is adjusted so thepower of input signal S_(Input5) and output signal S_(Output5) areadjusted, and the intensity of IR light 167 is driven to that indicatedby wavelength spectrum 196 b. In this way, the desired mixture of lightprovided by lighting system 100 b is chosen to correspond to awavelength spectrum of sunlight.

FIG. 10 is a block diagram of a lighting system 100 c, which includes aprogrammable logic controller 133 operatively coupled to LED array 102through LED controller 130. Lighting system 100 c includes a timercircuit 134 operatively coupled to programmable logic circuit 133. timercircuit 134 can be of many different types, such as a 555 timer. 555timers are made by many different manufacturers. For example, ECGPhilips makes the ECG955M chip, Maxim makes the ICM7555 chip andMotorola makes the MC1455/MC1553 chip.

Timer circuit 134 provides a timing signal S_(Timer) to programmablelogic circuit 133 and, in response, programmable logic circuit 133provides input signals S_(Input1), S_(Input2), S_(Input3), S_(Input4)and S_(Input5) to LED controller 130. As discussed in more detail abovewith FIGS. 6 a and 6 b, as well as with FIGS. 7 a-7 e and FIGS. 8 a-8 e,LED controller 130 provides input signals S_(Output1), S_(Output2),S_(Output3), S_(Output4) and S_(Output5) to LED array 102 in response toreceiving input signals S_(Input1), S_(Input2), S_(Input3), S_(Input4)and S_(Input5).

In this embodiment, programmable logic controller 133 is programmed toadjust input signals S_(Input1), S_(Input2), S_(Input3), S_(Input4) andS_(Input5) response to receiving timing signal S_(Timer). Programmablelogic controller 133 can adjust input signals S_(Input1), S_(Input2),S_(Input3), S_(Input4) and S_(Input5) in response to receiving timingsignal S_(Timer) in many different ways.

In one example, programmable logic controller 133 adjusts input signalsS_(Input1), S_(Input2), S_(Input3), S_(Input4) and S_(Input5) inresponse to receiving timing signal S_(Timer) so that the relativeintensities of light 160, 162, 163, 166 and 166 of FIG. 9 a are adjustedrelative to each other, as described in snore detail with FIGS. 9 a-9 g.In this way, lighting system 100 c includes a programmable logic circuitwhich adjusts input signals in response to receiving a timing signalfrom a timer.

In general lighting system 100 c allows the intensities of light 160,162, 163, 166 and 167 to be adjusted relative to each other as a periodof time. The period of time can have many different values. For example,in some embodiments, the period of time is in a range from about half anhour to more than one hour. In other embodiments, the period of time isin a range from about a day to several days. The period of time can alsobe in a range from a day to a week or more, or from a day to a month ormore, in one particular embodiment, the period of time corresponds withthe yearly cycle of the sun so that lighting system 100 c mimics thesun.

The embodiments of the invention described herein are exemplary andnumerous modifications, variations and rearrangements can be readilyenvisioned to achieve substantially equivalent results, all of which areintended to be embraced within the spirit and scope of the invention asdefined in the appended claims.

1. A lighting system, comprising: an LED array which includes first andsecond LED sub-arrays; a first input operatively coupled to the firstLED sub-array through a controller; and a second input operativelycoupled to the second LED sub-array through the controller; whereinfirst and second wavelength spectrums provided by the first and secondsub-arrays, respectively, are adjustable in response to adjusting firstand second input signals provided to the first and second inputs,respectively.
 2. The system of claim 1, wherein the first LED sub-arrayincludes first, second and third light emitting diodes which emit first,second and third colors of light, respectively.
 3. The system of claim2, wherein the intensities of the first, second and third colors oflight are adjustable relative to each other in response to adjusting thefirst input signal.
 4. The system of claim 2, wherein the second LEDsub-array includes fourth, fifth and sixth light emitting diodes whichemit fourth, fifth and sixth colors of light, respectively.
 5. Thesystem of claim 2, wherein the intensities of the fourth, fifth andsixth colors of light are adjustable relative to each other in responseto adjusting the second input signal.
 6. The system of claim 1, whereinthe first and second input signals are adjusted to drive the first andsecond wavelength spectrums to match the action spectrum of thephysiological activity of a plant.
 7. The system of claim 1, wherein thefirst and second inputs are adjusted to drive the first and secondwavelength spectrums to match the action spectrum of the physiologicalactivity of first and second plants, respectively.
 8. A lighting system,comprising: a controller; an LED array which includes first and secondLED sub-arrays, wherein the LED array is operatively coupled to thecontroller; a first input operatively coupled to the first LED sub-arraythrough the controller; and a second input operatively coupled to thesecond LED sub-array through the controller; wherein first and secondwavelength spectrums provided by the first and second sub-arrays,respectively, are adjustable to match an action spectrum of a plant inresponse to adjusting first and second input signals provided to thefirst and second inputs, respectively.
 9. The system of claim 8, whereinthe first LED sub-array includes first, second and third light emittingdiodes which emit first, second and third colors of light, respectively.10. The system of claim 9, wherein the first and second colors of lightare red and green light, respectively.
 11. The system of claim 10,wherein the third color of light is different from the first and secondcolors of light.
 12. The system of claim 10, wherein the third color oflight has a wavelength between about 40 nanometers to about 380nanometers.
 13. The system of claim 10, wherein the third color of lighthas a wavelength between about 750 nanometers to about 2500 nanometers.14. The system of claim 10, wherein the third color of light has awavelength between about 660 nanometers to about 700 nanometers.
 15. Thesystem of claim 8, wherein the first and second inputs are adjusted todrive the first and second wavelength spectrums to match the actionspectrum of the physiological activity of a plant pigment of the plant.16. The system of claim 8, wherein, the first and second inputs areadjusted to drive the first and second wavelength spectrums to match thewavelength spectrum of sunlight.
 17. A lighting system, comprising: afirst LED array which includes a plurality of LED sub-arrays; aplurality of inputs operatively coupled to a corresponding LED sub-arraythrough a controller; wherein the intensity of light emitted by the LEDsub-arrays is adjustable in response to adjusting input signals provideto the inputs; a programmable logic circuit operatively coupled to theinputs, and a timer operatively coupled to the programmable logiccircuit; wherein the programmable logic circuit adjusts the inputsignals in response to receiving a timing signal from the timer.
 18. Thesystem of claim 17, wherein the intensity of light emitted by the LEDsub-arrays is adjustable, in response to adjusting the input signals, todrive a wavelength spectrum of the first LED array to match the actionspectrum of the physiological activity of a plant.
 19. The system ofclaim 17, wherein the intensity of light emitted by the LED sub-arraysis adjustable, in response to adjusting the input signals, to drive awavelength spectrum of the first LED array to match the action spectrumof the physiological activity of a plant pigment.
 20. The system ofclaim 17, wherein the intensity of light emitted by the LED sub-arraysis adjustable, in response to adjusting the input signals, to drive awavelength spectrum of the first LED array to match the wavelengthspectrum of sunlight.